Electro-optical printer

ABSTRACT

An electro-optical printer is implemented with an electro-optical character generator in combination with an illumination sensitive medium such as photographic paper. This printer arrangement provides advantages such as being compatible with liquid crystal display devices used on conventional calculators and provides hard-copy printouts with a non-impact printer arrangement.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of parent application Electro-OpticalPrinter by Stanly and Hyatt Ser. No. 754,647 filed on Dec. 27, 1976 nowU.S. Pat. No. 4,236,223 issued on Nov. 25, 1980 and copending herewith;where said parent application is herein incorporated by reference andwhere the benefit of the filing date of said parent application isherein claimed in accordance with 35 USC 120, 35 USC 121, and otherauthorities provided therefor.

This application is related to application Illumination Control SystemSer. No. 366,714; filed on June 4, 1973; by Gilbert P. Hyatt now U.S.Pat. No. 3,986,022 issued on Oct. 12, 1976 and applicationElectro-Optical Illumination Control System; Ser. No. 730,756; filed onOct. 7, 1976; by Gilbert P. Hyatt; now abandoned in favor of continuingapplications wherein these applications are hereinincorporated-by-reference as if fully set forth at length herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to digital printers.

2. Description of the Prior Art

The prior art provides many different types of printer devices such ascharacterized by the art of record herein. These printers are relativelylarge and expensive and do not lend themselves to low-cost consumerapplications such as for electronic calculators. Therefore, prior artlow-cost electronic calculators have only operator displays but do nothave hard-copy printers. The prior art is further described in thereferences cited in this case.

SUMMARY OF THE INVENTION

The present invention provides a simple, inexpensive, and portabledigital printer system for use in products such as low-cost electroniccalculators. It may be implemented as a character printer, as a lineprinter, and as a page printer as a compromise between speed and cost.The printer of the present invention may utilize conventional liquidcrystal display (LCD) characters which are commonly used in the priorart for operator displays. Such display-type LCD characters may beilluminated to selectively expose an illumination sensitive medium forrecording or photographically printing the illuminated characters.Exposure may be provided with a contact print arrangement or with aprojection (focused image) print arrangement depending upon theapplication.

An objective of the present invention is to provide a low-cost andportable hard-copy recorder.

A further objective of the present invention is to provide a low-costand portable printer system.

A still further objective of the present invention is to provide aprinter that is compatible with electronic displays.

The foregoing and other objects, features, and advantages of the presentinvention will become apparent from the following detailed descriptionof the preferred embodiments of this invention, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the invention may be had from considerationof the detailed description hereinafter taken in conjunction with thedrawings described below.

FIG. 1 is a block diagram representation of a printer in accordance withthe present invention.

FIG. 2 is a diagram of a liquid crystal multiple-element segment displaythat may be used in accordance with the present invention.

FIG. 3 is a diagram of a contact print embodiment of the presentinvention in accordance with FIG. 1.

FIG. 4 is a diagram of a projection embodiment of the present inventionin accordance with FIG. 1.

FIG. 5 is a diagram of a combination display and printing embodiment ofthe present invention in accordance with FIG. 1.

FIG. 6 comprises FIG. 6A showing a preferred embodiment of a printingcharacter and FIG. 6B showing alphanumeric printing characters.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT

The system of the present invention represents a basic teaching in theprinter art, providing exposure of an illumination sensitive medium forrecording digital information under control of an electro-opticaldevice. For simplicity of discussion, the general teachings of thepresent invention will be discussed in the presently preferredembodiment of a printer for an electronic calculator using liquidcrystal display (LCD) image generators.

A preferred embodiment of the printer is shown in FIG. 1, which isrelated to FIG. 1 of the referenced Illumination Control System patent.An illumination source 100 generates illumination 102 to illuminateillumination control device 1422 to illuminate the illuminationsensitive medium 130. Source 100 may be used with a reflector 1441 toconcentrate illumination 102 toward medium 130. Control device 1422 mayoperate in response to signals 133 from a command and control device127, 128 which may be a well-known prior art calculator such as model2230 manufactured by Litronix, Inc of Cupertino, Calif. Illuminationsensitive medium 130 may be transported past illumination control device1422 with well-known paper or film handler devices. For example, film130 may be stored on roll 24 and may be transported past control device1422 as shown with arrow 23 with capstan 25 and idler wheel 26. Filmtransport mechanism 24-26 may be controlled to transport an exposedportion past control device 1422 and to stop for exposure of a newunexposed portion or may be controlled to drive continuously. Such drivemechanisms are well known in the art such as for paper feeds and inmagnetic tape cassette recorders for tape drives. Source 100 may be awell-known flash tube such as a xenon flash tube to provide a rapidillumination strobe to rapidly expose medium 130 in order to mitigatethe effects of motion such as blurring of images. Control electronicsfor xenon flash tubes and other illumination sources are well known inthe art. Alternately, a pulse modulated control is discussed in thereferenced Illumination Control System patent relative to FIG. 2 thereinwhich may be used for controlling source 100. Alternately, source 100may be continuously excited and exposure may be accomplished bycontrolling electro-optical device 1422, as discussed in the referencedIllumination Control System patent relative to FIGS. 8 and 9 therein forelectro-optical shutters and apertures. In this electro-optical shutterembodiment, electro-optical device 1422 may be controlled to bereflective (assuming a transmissive mode of operation) until medium 130is in printing position and then the selected electro-optical segmentsmay be controlled to be transmissive for printing of those segments onmedium 130.

Electro-optical device 1422 controls input illumination 102 toselectively expose medium 130 at the appropriate time. Strobing of theprinting operation can be performed with pickoffs on the mechanicalelements of the medium feed in the manner conventionally used withhammer-type impact line printers such as manufactured by Data ProductsCorporation of Woodland Hills, Calif. Electro-optical device 1422 may bea single character printer, a line printer, or a page printer; whereinprior art single character printers are exemplified by a conventionaltypewriter and prior art line printers are exemplified by Data ProductsCorporation impact line printers. Strobing of the printing operation maybe performed with conventional techniques such as used with the TeletypeCorporation ASR-33 printer as a character printer and said Data ProductsCorporation printer as a line printer. In direct contrast to those priorart mechanical printers, character selection for the printer of thepresent invention is performed electro-optically rather thanmechanically.

In addition, source 100 may be electronically controlled with controlsignal 132. This control signal may be generated from an illuminationfeedback transducer signal or other control signal as discussed in thereferenced copending applications.

Electro-optical formation of characters to be printed are well known inthe display art, although they are not well known in the printing art.For example, LCDs and LCD command devices are widely used withelectronic watches, panel meters, calculators, and other display deviceswhere the LCDs and related LCD command devices may be used to implementand to command illumination control 1422 of the present invention. Onesuch well-known prior art display arrangement is briefly discussed withreference to FIG. 2 hereinafter.

Illumination 102 processed with control 1422 exposes medium 130 as it istransported with transport mechanism 24-26. Illumination sensitivemedium 130 may be any well-known medium but in a preferred embodiment itis illumination sensitive recording paper such as used in conjunctionwith recording oscillographs of the VISICORDER type provided byHoneywell Test Instruments Division in Denver, Colo. and other suchoptical oscillograph-type recorders. Such oscillograph recording mediumhas particular advantages in that it may be used with ambient lightingand does not need a darkroom nor a cartridge, nor camera enclosure forcontrolling exposures. Alternately, medium 130 may be photographic filmwhich may be used in conjunction with conventional camera devices forcontrolled exposures independent of ambient illumination conditions. Inother embodiments, medium 130 may be infrared or thermal sensitive, maybe ultra-violet sensitive, or may be other sensitive devices.

Priner 21 may provide a primary exposure with source 100 and a secondaryexposure with source 40. The primary exposure may be performed at arelatively higher intensity with a source such as a xenon, mercuryvapor, or fluorescent lamp for exposing medium 130 with a character. Thesecondary exposure may be performed at a lower intensity with a lampsuch as a fluorescent lamp for photodeveloping medium 130.

In another embodiment, medium 130 may be a thermal developing mediumsuch as Kodak type Ektamate 150 using thermal developing device 40 tothermally develop medium 130. Developing device 40 may be a heaterelement, a heated medium guide, a heated plenium chamber, or other sucharrangement. Alternately, medium drive devices such as capstan 25 andwheel 26 may be heated such as with a heater element 25 forphotodeveloping medium 130.

Control device 1422 may include an electro-optical character generator104 such as the liquid crystal display (LCD) 104 shown in FIG. 2. LCD104 may include a single character 27 to implement a character printer,may include a line 30 of a plurality of characters 27-29 to implement aline printer, or may include a plurality of lines of characters 30 and31 to implement a multiple-line printer or a page printer. Eachcharacter may be implemented as a conventional display such as aseven-segment display shown as character 27. Other character displayarrangement such as alpha-numeric segment display arrangements are wellknown in the art and may also be used to implement control 142.Characters may be sequentially excited such as controlled withwell-known display refresh electronics or may be all excitedsimultaneously for a parallel printing operation such as controlled withwell-known constant excitation display electronics.

Because electro-optical device 104 may be similar to, if not identicalto, a well-known liquid crystal display; the visual display itself maybe used to provide the dual function of display to an operator andprinting on an illumination sensitive medium. Alternately, redundantelectro-optical devices may be used wherein a first electro-opticaldevice may be used as an operator display and a second electro-opticaldevice may be used for exposing illumination sensitive medium 130; whereboth the display and the exposing electro-optical devices may becontrolled from the same control device and/or with the same controlsignals or both. Therefore, the compatibility of the electro-opticaldevice in the printer of the present invention with the prior artelectro-optical display devices provides advantages of compatibility andinterchangeability. Alternately, different types of display and printingelements may be used wherein the display element may be a well-knownlight-emitting diode display and the printing element may be an LCDelement as discussed with reference to FIGS. 1-6 above.

A contact print embodiment will now be described with reference to FIG.3. Illumination 102 from source 100 may be used to illuminateelectro-optical device 1422 which may be controlled to providealpha-numeric character images. Character images from electro-opticaldevice 104 may be contact printed on medium 130 with exposing device 104as medium 130 is transported past device 104 in the direction of arrow23. Illumination 102 may be diffused or otherwise optically preprocessedto provide the desired uniformity and illumination density across device104. This contact print embodiment represents a presently preferredembodiment because of the simplicity of contact printing compared toprojection printing.

A projection illumination control embodiment will now be described withreference to FIG. 4. Illumination 102 from source 100 may be processedwith first processing optical devices 1433 such as accumulating lensesto provide preprocessed illumination 1434 to illuminate electro-opticaldevice 104. Electronic control of device 104 permits selected segmentsto form digital character illumination images with controlledillumination 1435 which may be focused with second processing optics1436 to generate postprocessed illumination 108 for exposing medium 130,transported in the direction shown with arrow 23. Postprocessing optics1436 may include focusing lenses to focus the image to be printed onmedium 130.

A combination printing and display arrangement consistent with thecontact printing embodiment described with reference to FIG. 3 and theprojection printing embodiment described with reference to FIG. 4 willnow be described with reference to FIG. 5. Illumination 102 from source100 or illumination 1434 from optics 1433 may be formed into characterimages with LCD 104 as discussed above. Illumination image 1435 may beprocessed with beam splitter 42 which may be included in optics 1436(FIG. 4). Beam splitters are well known in the art and may be formed asa prism 42 with a half-silvered surface such as surface 43. Illumination1435 having character images impressed thereon may be transmittedthrough optic device 42 to beam splitter surface 43 to generatetransmitted image 46 and reflected image 45. Transmitted image 46 may beused for display purposes such as by illuminating a frosted glass screenwhich may be surface 43 of optics 42 formed in frosted form or which maybe a separate projection screen illuminated by image 46. Reflected image45 may be used for printing on medium 130 which may be transported asshown with arrow 23; as discussed with reference to FIGS. 1-4 above.Alternately, reflected image 45 may be used for display and transmittedimage 46 may be used for printing.

Still further, beam splitter 42 may be electronically controlled such asby implementing surface 43 as a liquid crystal device which may becontrolled to be reflective for printing, or to be transmissive fordisplay, or to be partially reflective and partially transmissive forcombinations of printing and display; wherein partial and fullreflectivity and transmissivity are disclosed in the referenced patentIllumination Control System.

Well-known prior art devices may be used in various combinations toimplement the preferred embodiments of the present invention. Forexample, source 100, photodeveloper lamp 40, medium 130, medium feed24-26 and projection optics 1433 and 1436 may be implemented as providedin the Honeywell VISICORDER product; command and control devices 127 and128 and LCD character generators 27 and 104 may be implemented asprovided in display calculators, LCD digial watches, LCD panel meters,and other well-known display devices; illumination sensitive medium 130may be Kodak direct print photodeveloping paper type 2167 or type 2295or thermal developing paper type Ektamate 150. Thermal developing may beperformed with well known heater elements such as resistance heaters,gas heaters, etc and thermal developing may be performed by passingmedium 130 over a conduction surface such as a guide, capstan, orroller; through a convection heating region, or through a radiationheating region; by illuminating and simultaneously heating withradiation such as infrared illumination; and may be other well-knownmeans and methods for heating.

A preferred character generation arrangement will now be discussed withreference to FIGS. 1, 6A, and 6B. As discussed above, medium 130 istransported past illumination control 1422 for exposure, where medium130 may be exposed while moving in the direction off arrow 23 or may bestopped for exposure. In the moving exposure embodiment, the charactersmay become smeared by motion of the medium, which smearing is generallyconsidered by the art to be detrimental and undesirable. In accordancewith another feature of the present invention, a character generator isprovided that utilizes this smearing effect to facilitate propercharacter printing.

The prior art method may be characterized as spacial-domain printingwhere the character is completely defined in the two-dimensional planeof the character generator and paper and where the instant feature ofthe present invention may be characterized as time-domain printing wherethe character is not completely defined in the spacial-domain but isdependent upon time, the smearing effect, and/or motion of the medium toproperly form the character.

A seven-segment alphanumeric character is illustrated in FIG. 6A and tennumeric characters and several alphabetical characters are illustratedin FIG. 6B which are formed from the alphanumeric character of FIG. 6Ain accordance with the time-domain character generation feature of thepresent invention. These characters have relatively wide segments 51parallel to the direction of motion (vertical in FIGS. 6A and 6B) andhave relatively thin segments 52 across or perpendicular to thedirection of motion (horizontal in FIGS. 6A and 6B); where motion isdepended upon to increase the width of thin segments without increasingthickness of thick segments 51 parallel to the direction of motion.Conventional segments are separated by spaces such as the seven-segmentcharacter 27 (FIG. 2). For convenience of illustration, the charactersegments in FIG. 6 are not shown with such spaces. Nevertheless, anactual embodiment may implement alphanumeric character 50 (FIG. 6A) andcharacters 54 (FIG. 6B) having segments with spaces therebetween or withother well-known formats.

Alphanumeric character 50 is printed by exposing illumination sensitivemedium 130 as medium 130 is moved in the direction shown by arrow 23(FIG. 1 and FIG. 6A). As medium 130 is moved past character 50 in thedirection of arrow 23, segments perpendicular to the direction of motion(horizontal segments) such as segment 52 may be smeared in the directionof motion 23 as shown by the crosshatched symbol in FIG. 6A to theposition illustrated with the dashed lines such as dashed line 53.Segments parallel to the direction of motion (vertical segments) such assegment 51 may not be smeared to an appreciable degree, although theremay be some degree of smearing of segments parallel to the direction ofmotion such as indicated in the bottom of segment 53.

The width of horizontal segments 52 may be determined by the amount ofsmearing that will occur due to motion 23 during the exposure period.For example, if the exposure period and the velocity of motion caused asmearing of three-quarters of the width of a vertical segment 51 duringan exposure period, then horizontal segments 52 need only have a widthof one-quarter the width of the vertical segments because the otherthree quarters of the width will be exposed as a function of thesmearing effect due to motion 23. The faster the motion 23 and thelonger the exposure time, the wider will be the exposed horizontalsegments 52.

The smeared horizontal segments 52 have a lower exposure than theunsmeared vertical segments 51 because horizontal segments 52 are onlyexposed for a portion of the exposure period due to the motion 23 andthe resulting smearing effect while vertical segments 51 receive higherlevels of exposure because of the substantially continuous exposureduring the complete exposure period. Because of the relatively highexposure intensity levels and because latitude or shades of grey neednot be implemented, even the low exposure of horizontal segments 52 maybe substantially indistringuishable from the higher level exposures ofvertical segments 51.

Alphanumeric characters may be formed with the single alphanumericcharacter type shown in FIG. 6A. Ten numeric characters 0 to 9 andseveral alphabetical characters A, B, I, and O are shown in FIG. 6B;where vertical segments are shown wider than horizontal segments.Exposure of such characters using time-domain techniques described abovewill cause the width of horizontal segments to be increased from thewidth shown for the characters in FIG. 6B.

In view of the above, a time-domain character generator may be providedin place of the prior art spacial-domain character generator wherein thetime-domain character generator makes use of the smear effect due tomotion of the medium in contrast to prior art character generatorswherein the smearing effect is considered to be detrimental. Thetime-domain character generator has many advantages such as reducing theeffect of smearing of characters and facilitating printing on the flywhile the medium is in motion.

Because of the flexibility of the illumination printing feature of thepresent invention, many different printing alternatives now becomeavailable. For example, medium 130 may be continuously moved pastprinting illumination 108 for higher speed operation such as with acomputer printout device using the time-domain printing arrangement. Theliquid crystal device may be controlled to first form characters forexposure and then to become a shutter for non-exposure between lines ofprinted information. Alternately, medium 130 may be stopped at eachline, such as for intermittent printing as with a desk-top calculatorusing spacial-domain characters and the illumination amplifier shutterof U.S. Pat. No. 3,986,022. Alternately, the continuous motionarrangement may be used in combination with a high intensityillumination source and a short printing period to minimize smearingusing spacial-domain characters.

In accordance with another feature of the present invention,illumination source 100 (FIG. 1) may provide both exposure illuminationand developing energy. For example, medium 130 may be a thermaldeveloping medium which is conventionally believed to requireillumination for exposure and heat for developing. It has been foundthat illumination source 100 may provide both exposure and developingenergy. For example, a high intensity source 100 may be used to "burnin" the characters with high intensity illumination for exposing medium130. Alternately, heat generated by source 100 may be used to heat theenvironment of medium 130 such as the structure or the air for thermaldeveloping with energy from illumination source 100.

Another feature of the present invention may be characterized as adisplay-before-print feature. Because of the well-known nature ofmicroprocessor technology, the use of microprocessors in desk-topcalculators, the use of displays in desk-top calculators, and the use ofprinting mechanisms in desk-top calculators; the display-before-printcapability can be implemented from the discussion thereof hereinafter.

Another feature of the present invention provides the combination of adisplay and a printer in the same system. This permits an operator toview output information before printed information is visually availablesuch as where the case obscures the most recently printed information.Also, information may be displayed before printing to facilitatedetection and correction of errors. In one embodiment, outputinformation may be displayed after being processed without beingprinted. The operator may be required to separately command printingsuch as with a special print command key on the keyboard or alternatelyby depression of a function command key on the keyboard. A buffer memorymay be used to store information not yet printed for subsequent printingwith the appropriate operator command. In use, an operator may enterinformation from the keyboard; visually verify the information on thedisplay; then depress a key such as a print key, a function key, orother key for printing after the displayed information has been verifiedto be correct. If an error were detected, the error may be corrected asprovided with prior art display calculators. Correct information couldbe printed by depression of the appropriate key. For example, a clearkey may be used to clear an erroneous display without printing and afunction key such as plus, minus, multiply, or divide may be used toprint the properly displayed information.

The display-before-print feature of the present invention may beimplemented with a shutter arrangement for controlling printing anddisplaying. Alternately, separate character generators may be providedfor independent printing and display. As shown in FIG. 5, surface 43 maybe a liquid crystal shutter surface which controls whether illumination1435 is transmitted for display as illumination 46 or for printing asillumination 45. Device 43 may be controlled for either display orprinting, or for display only, or for display and printing such as withfully transmissive and partially transmissive surface 43.

Several techniques for providing thermal developing will now bediscussed. In one embodiment, radiant heating may be provided such asradiant energy from illumination source 100. In another embodiment, atransparent heating element may be provided such as with conductionheating from a heating element, wherein the transparent heating elementmay permit viewing of the printed characters as they are being thermallydeveloped. Alternately, the back side of medium 130 may be heated withan opaque heating element either in place of or in addition to atransparent heating element. Temperature control may be provided with atemperature transducer and a temperature controller for controlling aheating element as is well known in the art. The transducer may sensethe temperature of one of the heating surfaces or alternately may be incontact with the printing medium and may sense temperature of theprinting medium as it is being thermally developed.

Alternately, a ratchet-type arrangement for paper feeding with a paperpush plate may be provided, wherein the push plate used to move thepaper may also be heated with a heating element to provide for thermaldeveloping during paper feed operations. In another embodiment, aresistive medium such as graphite impregnated illumination sensitivepaper may be heated resistively by applying a voltage across the paperfor thermal developing.

In one embodiment, a single illumination source may be provided for bothillumination printing and either photodeveloping or thermal-developing.In an alternate embodiment, a single source may illuminate the printingarrangement along a first illumination path for printing operations andmay illuminate the medium along a second illumination path forphoto-developing or thermal-developing such as by using light-pipeelements to conduct illumination. In this embodiment, a light pipe maybe an illumination transmissive and conductive medium such as lucite ora thermal conductive medium such as copper to conduct light or heatenergy respectively. For example, illumination may be separatelyconducted along a first path for printing and along a second path forphoto-developing with fiber optic or lucite light pipes. The two pathsmay be different therebetween, where one path may conduct a higherintensity illumination than the other path such as for higher intensityfor printing and lower intensity for developing or conversely lowerintensity for printing and higher intensity for developing.

The environment for the printer systems of the present invention isdiscussed in greater detail in the copending patent applicationIllumination Control System which is herein incorporated-by-reference.Although the pertinence thereof will be readily apparent from thecontext of the instant application and the context of said copendingapplication, the more pertinent aspects with reference to the figures ofsaid copending application and with the text related to said figureswill be briefly discussed hereinafter.

FIG. 1 of said copending application shows command device 127, which maybe a microcomputer in an electronic calculator, generating commandsignal 126 to command signal processor 128, which may be controlelectronics, to generate control signal 132 to control illuminationsource 100 for illuminating electro-optical device 104 with controlledillumination 102. Segment control signals for the LCD may be signals 133to illumination amplifier 104 which may be an electro-signal charactergenerator. Illumination 108 having the character image impressed thereonexposes illumination sensitive medium 130 in receiver 112. Illuminationfeedback may be provided with feedback transducer 134 and feedbacksignal processors 116.

FIG. 2 of said copending application shows generation of control signalfor electro-optical devices with gates 210 or SCRs 216 using segmentcontrol signals 212 and 218 respectively. Alternately, computer 251 maycontrol segments either in a feedback arrangement as discussed for FIG.2C or without feedback. Pulse modulation may be used, as shown in FIGS.2B and 2D therein.

FIGS. 3-7 of said copending application show specific applicationswherein the text related thereto provides alternate embodiments to theprinter embodiment discussed herein.

FIG. 8 of said copending application shows segment control ofillumination for exposing an illumination sensitive medium and thereforeis directly applicable to the segment control and medium exposure of thepresent invention.

FIGS. 9 and 10 of said copending application provide camera systems forexposing an illumination sensitive medium wherein the printingarrangement of the present invention may be configured in the form of acamera system, particularly for the projection embodiment discussed withreference to FIG. 4 herein.

FIG. 11 of said copending application provides a segment controlarrangement which is applicable to the control of electro-opticalsegments of the printer of the present invention.

Elements 1422, 1433-1436, and 1441 are described in greater detail incopending patent application Electro-Optical Illumination Control Systemparticularly at FIG. 14 therein, herein incorporated-by-reference.

In view of the above, the disclosures in said copending applications aredirectly applicable to the system of the instant invention and provide adetailed basis for the inventive features discussed herein.

In view of the above, it can be clearly seen that the present inventionprovides a novel means and method for printing digital information suchas for use in an electronic calculator.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is susceptible to modification in its form, proportions,operation, detailed implementation and arrangement of parts withoutdeparting from the teachings of the present invention.

In order to comply with the statute, the invention has been described inspecific language related to a preferred embodiment. It is intended thatthe invention not be limited to the specific features shown, but thatthe means, method, construction herein disclosed comprise the preferredform of several modes of putting the invention into effect and theinvention is, therefore, claimed in all of its forms within thelegitimate and valid scope of the appended claims.

What we claim is:
 1. A printer system for printing digital information,said printer system comprising:command means for generating electricalcommand signals related to digital information to be printed; anillumination source for generating illumination; illuminationcontrolling means for generating controlled illumination by controllingtransmission of the illumination from said illumination source inresponse to the command signals; means for projecting the controlledtransmitted illumination from said illumination controlling means ontoan illumination sensitive medium; and means for printing digitalinformation by exposing an illumination sensitive medium in response tothe controlled illumination from said illumination controlling means. 2.The system as set forth in claim 1 above, wherein said illuminationcontrolling means includes a plurality of segments for exposing saidillumination sensitive medium with a digital character.
 3. The system asset forth in claim 2 above, wherein said printing means includes meansfor transporting and illumination sensitive medium past saidillumination controlling means to sequentially expose said illuminationsensitive medium with a plurality of the digital characters.
 4. Thesystem as set forth in claim 1 above, wherein said printing meansincludes means for providing contact exposure of an illuminationsensitive medium.
 5. The system as set forth in claim 1 above, whereinsaid projecting means includes means for providing projection exposureof an illumination sensitive medium.
 6. The system as set forth in claim1 above, wherein said command means includes means for calculatingnumerical solutions and wherein said printer system provides hard-copyoutput for the calculated numerical solutions.
 7. The system as setforth in claim 1 above further comprising an operator display fordisplaying numerical information in response to the command signals. 8.The system as set forth in claim 1 above, wherein said illuminationsource includes means for generating the illumination as visibleillumination.
 9. The system as set forth in claim 1 above, wherein saidillumination source includes means for generating the illumination asinfra-red illumination.
 10. The system as set forth in claim 1 above,wherein said illumination source includes means for generating theillumination as coherent illumination.
 11. The system as set forth inclaim 1 above, wherein said illumination source includes means forgenerating the illumination as ultra-violet illumination.
 12. The systemas set forth in claim 1 above, wherein said command means includes pulsemodulation means for generating the electrical command signals as pulsemodulated electrical command signals.
 13. The system as set forth inclaim 1 above, further comprising feedback means for controlling thecontrolled transmitted illumination from said projecting means.
 14. Anumerical recording system comprising:an electronic calculator forgenerating an output signal in response to numerical calculations;liquid crystal means for generating at least one numerical characterillumination image in response to the output signal; and exposing meansfor contact exposing an illumination sensitive chemical medium inresponse to the illumination image.
 15. The system as set forth in claim14 above further comprising display means for displaying a numericalcharacter in response to the output signal.
 16. The system as set forthin claim 14 above further comprising means for displaying theillumination image.